package com.gosophia.util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 处理代理服务器缓存问题
 * 
 * @author zhao_yanfang
 * 
 */
public class NoCachingFilter implements Filter{

	private FilterConfig filterConfig;

	public void destroy() {

	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		HttpServletResponse httpResponse = (HttpServletResponse) arg1;
		httpResponse.setHeader("Cache-Control ", "no-cache ");
		httpResponse.setDateHeader("Expires ", 0);
		httpResponse.setHeader("Pragma ", "No-cache ");
		arg2.doFilter(arg0, arg1);
	}

	public void init(FilterConfig arg0) throws ServletException {
		this.filterConfig = arg0;
	}
}
